Inner tube and method of making the same



H.. DECH. INNER TUBE AND METHOD OF MAKING THE SAME. APPLICATION FILEDAUG.I4, 191a.

Pat ented May 18,1920.

HENRY DECH, F TRENTON, NEW JERSEY, AssIsNon TO Mnncian. Tm COMPANY, or

TRENTON, Nnw Jnn-snn-A conronetr onor'NEw Jnnsn INNER TUBE'ALID METHODoFIMAKINe THE SAME.

Patented May 18, 1920.

. Application filed August 14, 1918. Serial No. 249,808,

To all whom it may concern: I Be it known that I, HENRY Dnc'rr, acitizen of the United States, andresident of Trenton, in the county ofMercer and State of New Jersey, have invented ,a new and usefulImprovement in Inner Tubes and Methods" of Making the Same, of which thefollowing is a specification.

This invention relates to a rubber inner tube for pneumatic vehicletires and to a method for the manufacture of the same, with theparticular object inview of providing an inner tube which can have anyde-.

sired reinforcement. or thickness as to its tread portion or outerperiphery.

Another object. consists in providing a method whereby tubes ofsuchcharacter may be expeditiously manufactured and the material; ofwhich the tube is composed vulcanized in substantiallythe same shape asthat in which it is to be used.

Up to the present time it has been the general custom to manufactureinner tubes for pneumatic vehicle tires oneither straight or spiralcores or mandrels'. These tubes arecommonly very thin and of uniformthickness throughout. They serve as air-tight containers for the airwhich gives the tire its pneumaticcharacter, and their rupture by directpuncture or by abrasion, results in the deflation of the tire as awhole. the most frequent causes of deflation isthe cracking or breakingof the fabric which constitutes theinsidef of the outer shoe or casing,which cracking or breaking raises a ridge whichgradually chafesthrough-the comparatively thin inner tube.

l urthermore, any small, sharp article which manages to penetrate theouter shoe or casing 'of the tire will rapidly wear through the ordinarytube, and when even a email hole is formed in the casing, the airpressure within the tube will force the wall of the inner tubetherethrough and burst it.

, To obviate these disadvantages it has been suggested to eitherreinforce the outer portion of the tube with metal, fabric, etc, or tomake that portion of u the tube relatively thick. These suggestions havebeen found to' be impractical when the tubes were made on straight orspiral mandrels and by methods" now in common use.

mentioned and enables therapid and satis- Ithas been found thatone of'factorymanufacture of inner tubes with thickened tread portionsreinforced in any desiredand practical manner towithstand' wear. 1 vpractical embodiment of my invention and of one form of apparatus whichis. adapted for carrying out my improved method is shown in theaccompanying. drawings in which, W

Figure 1 represents a side elevatiomipartly broken away, of a'portioriof the coreor mandrel on which the tube is built and VH1. canized, thetube being shown inposition thereon.

Fig. 2 represents a side eleva'tion of the the details of the"structure. 7 a

F 1g. .3 represents an enlarged section taken in'the plane of the lineIlla-III of Fig. 7

looking in the directionofthet arrows, and v Fig. 4 represents anenlarged section taken inthe plane of thelinQIV-IV of'Fig. 2, 'lookinginthe direction of the arrows.

The core whichfforms the tube is denoted by '1, andis provided alongitsinner periphcry with recesses 52 and an intermediate 1 in a mannerand of materials wellknown to those skilledm the art. The tongue 3 ofthe core leaves agapinythe inner peripheral tongue 3. The tube is tuneuon the core a wall of the tube and the recesses 2form the adj acentedges ofthe tube into inwardly ex} tending ribs 4 which are sofashioned'by the tongue and walls of the: said recesses as tohave a pairof complementary grooves 5 and 6 on their inner and outer facesrespectively.

Thetube having been built upon the core 1, in the form described, is nowwound spirally" with fabric or tape and vulcanized in a manner wellknown in the art. After the vulcanization is finished, the tape isremoved and the tube stripped from the core 1.. A

clamping ring 7 which maybe made of steel,

iard rubber or any other suitable material, is now inserted into thetube through the" gap between the ribs 4. This ring is pro-. vided withdownwardly curving edges 8,

which are adapted to sea'tin the grooves '6 in the outer faces oftheribs 4. I i

A locking ring 9, which is preferably made of steel, and is circular incross section, is now forced between the ribs 4. and snapped into thegrooves 5. The ring 9 serves to force theribs into snug engagement withthe ring 7 and thus looks the edgesof fimshedtubei P t y ok away to Showthe tube together making it air-tight. A arranged to seat within theouter pair of suitable valve may be built into the tube and extended outthrough openings in the clamping ring and the locking ring, as shown at9* in Fig. 4. V v

The tube is now complete and may be used in the ordinary manner.

It will be observed that by the above method, the tube is completelybuilt and vulcanized in substantially the shape in which it is to beused and that the uniting of the edges of the tube does not require anyappreciable distortion of the tread portion or walls.

It; will be seen that the tube may be made of any desired thickness andmay be reinforced with any suitable or convenient ma terials for thepurpose of strengthening it.

I desire it to be understood that various changes may be resorted to inthe form, construction and arrangement of the tube and of the apparatusused in carrying out the method of manufacturing it, and in theparticular manner of conducting the steps of the method and in the orderthereof, without departing from the spirit and; scope of my invention;and hence I do notintend to be limited to'the details herein shown anddescribed except as they are specifically included in the claims.

What I claim is: r

1. An inner tube divided circumferentially along its inner wall, a.clamping ring located within the tube and adapted to engage the edges ofsaid inner wall for holding them together to form an air-tight tube, anda locking ring adapted to be seated between said edges to force theminto tight engagement with the clamping ring, j

2. An, inner tube divided circumferentially along its inner wall andhaving its adjacent edges provided with annular ribs projecting into thetube, the said ribs having a pair of outer complementary grooves, aclamping ring having side edges arranged to seat within the outer pairof grooves, and means for forcing the ribs into binding engagement withthe clamping ring.

3. An inner tube divided circumferentially along its inner wall andhaving its adjacent edges provided with annular ribs projecting into thetube, the said ribs having'pairs of inner and outer complementarygrooves, a clamping ring having side edges grooves, andv a locking ringarranged. to. seat within the inner grooves to force the ribs intobinding engagement with the clamping.

ring. v i

4;. Method of making an inner tube comprising the following steps:first, building up on a suitable core a tube blank having acircumferential gap in its inner wall and having its edges adjacent thegap formed into inwardly projecting ribs; second, vulcanizing the tubeblank; third, removing the tube blank from the core; fourth, insertinginto the tube blank clamping means ribs; and, fifth, inserting lockingmeans between the ribs to force them into tight engagement with theclamping means.

5.Method of making an inner tube comprising the following steps-z first,building up on asuitabl'ecore atube-blank having a circumferential gap.in its inner wall and havingits edges'adjacent the" gap formed intoinwardly projecting ribs; second, vuladapted to, engage the outer facesof the canizing thetube blank; third, removing the tube blank from thecore; fourth, inserting into the tube blank a clamping ring adapted toengage the outer faces of the ribs; and, fifth, locking the edges of thetube blank together by inserting a locking ring between i the ribs toforce the ribs into tight engagement with the clamping ring.

6. Method of making an inner-tube coma prising the following steps;first, building up on ajsuitable core a tube blank having acircumferential gap in its inner wall and having its'edges adjacent thegap formed into inwardly projecting ribs provided with complementarygrooves in their inner and HENRY DECH.

